An increase in the number of astrocytes, frequently observed in an irregular zone of variable definition adjacent to degenerative lesions (for example, encephalomalacia), focal inflammations (for example, abscesses), or certain neoplasms in the brain; in some instances, astrocytosis may be diffuse in a relatively large region; astrocytosis represents a reparative mechanism.
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References in periodicals archive ?
In our previous investigations, we have described the patterns of microglial activation [3, 4, 12, 35], astrocytosis [18], and WM damage [3, 4, 35, 36] using experimental models of stroke, excitotoxicity, and SCI.
All the abovementioned models support the amyloid cascade hypothesis; they show progressive A[beta] deposition in both diffuse and neuritic plaques, cerebral amyloid angiopathy, microgliosis, (limited) hippocampal atrophy, astrocytosis, synaptic and neurotransmitter alterations, and cognitive and behavioural deficits, relevant to human AD neuropathological profile [135-138].
It has been demonstrated that long term, chronic alcohol consumption causes reactive astrocytosis and enhances the release of proinflammatory mediators, mainly in brain regions such as the temporal cortex and hippocampus [34, 35].
Seven days after CSCI, areas of reactive astrocytosis and numerous astrocytes with thick cytoskeletal processes were noticed, indicating an upregulation of GFAP expression (Fig.
One case of low-grade astrocytoma was diagnosed as reactive astrocytosis of the brain, possibly due to erroneous sampling from the periphery of the main lesion.
Astrocytosis confirmed by GFAP immunostaining (GRAESSER et al., 2006) and microgliosis confirmed by Iba-1 immunostaining (SOFRONIEW & VINTERS, 2010) were also present in our case.
Morphologic diagnoses of the cerebellum included multifocal, subacute Purkinje cell degeneration, necrosis, with Bergmann's astrocytosis, granular cell atrophy, and chronic, locally extensive encephalomalacia with mineralization, gliosis, spongiosis, neovascularization, and gitter cell infiltration.
The impairment of this liver-specific metabolic pathway induced either by primary genetic defects or by secondary causes, namely associated with drugs administration, may result in accumulation of ammonia.3 Exposure of astrocytes in the brain to high levels of ammonia results in both cell swelling (acute exposure) and Alzheimer Type II astrocytosis (chronic exposure), (4) which causes consciousness disorder.
It has been demonstrated that "systemic administration of DHA after middle cerebral artery occlusion induces neurological recovery, reduces microglial infiltration, increases astrocytosis as early as 24h, and corresponds with the activation of AKT cascades as early as 4h after the onset of ischemia." (7)
The pathology showed neuronal necrosis, prominent reactive astrocytosis, microglial activation, and sparse mononuclear inflammation.
Saleem, "Abnormal neuronal migration, deranged cerebral cortical organization, and diffuse white matter astrocytosis of human fetal brain: a major effect of methylmercury poisoning in utero," Journal of Neuropathology & Experimental Neurology, vol.